Salmond said all parties would have to face up to the "electorate's judgment" after polling day on May 7, adding that Miliband had been "foolish" to rule out a coalition with the and suggested that he reacted because he was "under pressure from the Conservative press.”

Nicola Sturgeon enjoys a cup of tea with Alex Salmond while on the General Election campaign trail in Inverurie in the Gordon constituency

If the election resulted in a hung parliament, Salmond predicted the "most likely" outcome was an agreement by the SNP to support Labour on a vote-by-vote basis. "I think that after the election every Westminster politician will have to come and face the reality of the electorate's judgment," he told the BBC Radio 4 Today programme.

"There is no disrespect or disgrace in any politician coming to terms with the democratically expressed position of the electorate. All politicians, those of us who are lucky enough to be elected, chosen by the people, will try to do their best as they see it in the interests of the people who elected them."

Salmond also made clear that SNP MPs at Westminster would be prepared to vote on England-only issues - such as health and education where power has been devolved to the Scottish Parliament - if they impact on Scotland.

"The vast majority of votes have an economic impact," he said. "When I was a Member of Parliament before I voted against foundation hospitals in England because I thought it would lead to the fragmentation of the health service and then have effects in Scotland. I voted against tuition fees for English students in England. It is not English-only legislation, if it has an economic impact it has an impact on Scotland."

He indicated that the SNP could use their votes to try to change the Budget of the next government. "I don't think there is a single Member of Parliament or a single political party who wouldn't wish to be in a position and have an effect and influence for the betterment of their own constituents and, indeed, the betterment of politics across these islands," he said.